In the absence of a vaccine to prevent HIV infection, efforts to control the disease have focused on changing behaviors that place individuals at risk. While the assessment of HIV-related interventions with drug using populations has added significantly to our knowledge of risk behaviors and risk reduction strategies, major questions, from a public health perspective, remain unanswered. First, while much of this research has demonstrated that interventions can lead to short-term reductions in both drug and sex-related risk behaviors, studies on the long-term maintenance of low risk behaviors, or relapse to high risk behaviors, are generally lacking. Second, not all of those receiving interventions change their behaviors. Individuals who sustain or increase their risk behaviors likely represent the greatest threat to the rapid increase of HIV. Third, we know little about the effects of additional interventions on those previously involved in intervention impact studies. Fourth, few, if any, studies have compared the effects of interventions to behavior change in the absence of intervention. Additional understanding of the processes involved in behavior change, both within the individual and in the context of the drug using subculture, is clearly needed. The proposed study will be conducted with 1, 132 drug users who previously participated in the NIDA Cooperative Agreement study in Denver. Subjects will be randomly assigned to one of three conditions: a delayed intervention in which HIV testing and counseling is performed after the follow-up interview; a standard intervention in which HIV testing and counseling is delivered prior to the follow-up interview; or the standard plus an intensive intervention based on principles of motivational interviewing and "the street addict role". The relative effectiveness of these interventions will be assessed regarding reductions in HIV risk behaviors and maintenance of low risk. Longitudinal patterns of change in risk behaviors will be assessed across a span of over ten years. The impact of contextual factors (in particular, the street addict role) and psychological co-morbidity (anxiety, depression and anti-social personality disorder), on risk behaviors will also be assessed.